Sheet feeding apparatus



E. S. LINCOLN SHEET FEEDING APPARATUS Filed June 11,- 1930 5Sheets-Sheet l 3nventor W MVM (Ittomegl Aug. 9, 1932. E. s. LINCOLN 3 3SHEET FEEDING APPARATUS Filed June 11, 1950 5 Sheets-Sheet 2 T n S33nnentor C'a/W MOW/4mm Aug, 9, 1932.

E. s. LINCOLN SHEET FEEDING- APPARATUS Filed June 5 Sheets-Sheet 5 Ihwentor (Ittomeg 1932- E. s. LINCQLN 1,870,337

SHEET FEEDING APPARATUS Filed June 11, 1950 s Sheets-Shet 4 Snnentorattorney,

Aug. 9, 1932. E. s. LINCOLN SHEET FEEDING APPARATUS 5 Sheets-Sheet 5Filed June 11, 1930 Snvcntor Qttornegs Patented Aug. 9, 1932 unrrsnsures PATENT OFFICE nnwin s. LINCOLN, or scARsnALn Nnw YORK, ASSIGNOR TDEXTER FOLDER oom- PANY, on NEW YORK, N. Y., A CORPORATION on NEW YORKSHEET FEEDING APPARATUS Application filed June 11, 1930. Serial No.460,528,

This invention relates to'means for sepmating and lifting sheets one byone from a stack of such sheets, and more particularly to means forseparating and lifting sheets {of magnetic material.

Heretofore in apparatus of this character, much difiiculty has beenexperienced in preventingthe picking up of more than one sheet at atime. Due to the fact that metal lic sheets, of tin, for example, tendto stick together until air has been admitted between them, the secondsheet tends to be picked up with the top sheet. Moreover the magneticlifting flux tends to penetrate the top sheet into the second sheet andto liftjthe latter also,"'particularly where the sheets are stucktogether. However, when it is attempted to control the-magnetic flux toprevent such penetration, by cutting down the strength of the magnet orby concentrating the flux in a small sheet area, it is generally foundthat the lifting effort is too small.

One of the objects of this invention is to provide novel sheetseparatingmeans which will reliably separate sheets of'magnetic ma terial from astack at a rapid rate. Another object is to provide novel magneticlifting means whereby the flux does not penetrate through the top sheetto the second sheet, but yet sufficient lifting effort is obtained.

A. further object is to provide a novel lifting magnet which provides alifting flux of low density distributed overa large sheet area.

'A still further object is to provide novel operating means forliftingmagnets.

. Other objects will appear more fully hereinafter as the description ofthe invention proceeds.

Several embodiments of theinvention have been illustrated intheaccompanying drawings, but it is to be expressly understood that suchdrawings are forpurposes of illustration only and are not to. beconstrued as a Fig. 1 is a side elevation of an apparatus 7 embodyingthe invention;

Fig. 7 is a section through the solenoid adapted to operate the magneticlifters;

Fig. 8 is a side elevation of another embodiment of the invention; iFig. 9 is a top planview of Fig.8; and Fig. 10 is a wiring diagram forthe embodiment shown in Fig. 9. i

While the separating and feeding mechanism constituting the invention isbroadly adapted for and may be employed'in the separation and feeding ofsheets for any purpose, the drawings show the invention embodied in anapparatus for separating and feeding sheets of magnetic material, suchas tin, from a stack to a feed or conveying'table. Accordingly, asupporting frame 1 of any suitable construction and material, wherebythe separating and feeding mechanism is supported, is associated with afeed table 2 of any suitable type that is provided with conveyingrollers 3. A stack or pile of sheets' l, in this instance of tin, issupported by a suitable table 5 preferably provided with suitable sideregister devices 6. The table 5 is carried by an elevating mechanism ofany suitable type, and inthe form shown, rests on flights 7 secured toelevator chains 8, the latter passing over and being driven by sprocketwheels 9 mountedon a pair of shafts 10, one at each side of the frame.

For the purpose of rotating said sprocket wheels to drive the elevatorchains, each of the shafts 10 preferably carriesa worm gear 11 meshingwith a worm 12, the latter being mounted on a shaft 13 that rotates insuitable bearings formed on the frame'l. Any suitable means may beemployed to rotate the shaft13 to elevate the table 5, and in the formshown, an electric motor 1% which is suitably mounted on a bracketconstituting a part of the frame of the feed table 2 carries a pinion 16on its shaft meshing with an idler 17 which in turn drives a pinion 18on the shaft 13. Any suitable means, either manually or automaticallyoperated, may be provided to control the circuit of the motor 14 wherebythe top sheets of the stack are elevated tothe desired height at whichthey are maintained by means of a ratchet 19 on the shaft 13 with whichcooperates a pawl 20 that is carried by a shaft 21 mounted in theframe 1and provided on its outer end. with a handle 22. It is to be expresslyunderstood, however, that the above described pile elevating mechanismis shown for purposes of illustration only and constitutes no part perse of the present invention.

Suitable means are provided for separating and lifting the rear cornersor rear edge of the top sheet from the top of the pile andv forthereafter feeding the sheet off the pile.- 1n the form shown, wheresheets of: magnetic material are to be fed, the separating and liftingmeans preferably comprises magnetic lifters, preferably one for eachrear corner of the sheet, said lifters being preferably of a typehereinafter described that is particularly adapted to prevent thepenetration of the lifting flux through the top sheet; Said liftingunits are each designated as a whole by 23 and suitable means areprovided. for lowering the lifters into contact with the top sheet ofthe stack and for raising the same to lift the top sheet. In the formshown, each of the magnetic lifters 23 is lowered and raised by means ofa rockshaft 24 rotating in brackets 25 secured to the frame'l and.carrying-rock arms 26 on which the magnets are adjustably mounted bymeans of posts 27 through which the arms 26 pass. Preferably the shafts24 are oscillated by means of a solenoid 28 that is'mounted by means ofstraps 29 and arms 30, from rods 31 that are supported in the brackets25 and carry a cross arm 32 to which arms are attached. The operatingsolenoid 28- is shown in detail in Fig 7, and comprises a pair ofoperating coils33, separated by a non-magnetic plate 3 1, and pair ofplungers 35, one for each coil 33. When the coils33 are energized,plungers 35 are drawn into the coils toward the center, and preferablyhave a tight sliding fit so that they are cushioned to prevent impactagainst plate 34. The ends of plungers .35 may be bifurcated at 36 asshown in Fig.1 and pins 37 e7;- tend through said bifurcations andthrough slots in the ends of arms 38 that are secured to the rockshafts24. When the coils 33 are energized and the plungers-35 are pulled intothe coils, shafts 2d are rocks-(l by the arms 38 to raise the liftingunits 23 so as to pick up the rear corners of the top sheet, as clearlyshown in Figs. 1 and 2. When the solenoids are deenergized, the weightof the lifting units is suflicient to cause them to fall back intocontact with the next sheet, or if desired suitable resilient means orthe like may be employed to accomplish this end. d

When the rear corners of the sheet have been lifted as above described,the sheet is fed forwardly off the pile by means which as shown comprisea pair of reciprocating fingers 39'whichengage the lifted rear cornersand push the sheet forwardly until the forward edge thereof passes overa curved guide plate 10' and into engagement between rotating feedrollers 1-1 and 12. The fingers 39 may be reciprocated in any suitablemanner, and, as shown, are secured to horizontal rods 413 which extendslidably through suitable supporting members 44: and d5 at the front andrear of the apparatus respectively. A V-shaped bracket 46, the arms ofwhich are rigidly connected to the rods 43, is carried by the plunger 47of a solenoid 18, the latter being supported by straps 49 and brackets50 from the frame 1. Resilient means are provided for normallymaintainingthe fingers 39, rods 43 and plunger 17 in retracted position,said'means as shown comprising coil springs 51 surrounding each of therods 43 and interposed between the bracket 46 and the supporting member44. lVh'en the solenoid 1-8 isenergized, the plunger 47 is pulledforwardly against the tension of springs 51, whereby fingers 39 moveforwardly into engagement with the elevated rear corners of the sheetand push it forwardly until it is engaged by the feed rollers 41, 42 andfed off the pile to the conveying rollers 3' of the feed table 2. Anysuitable means may be em ployed for rotating said feed rollers, whichmeans may comprise a motor 52having a pinion 53 on its shaft that mesheswith an idler 5 1 which in turn engages one of a pair of inopposite.polarities so that the flux is uniformly distributed over the areacoveredby the unit. By this means the lifting flux which is necessary tolift the corner of the sheet is distributed over a'substantial area ofthe sheet so that the density of the flux passing through any oneportion of the sheetis kept low, with the result that sufficient liftingeffort is obtained without penetration of the magnetic flux through thetop-sheet.

Preferably, each ofthe magnet coils 58 adjustably carried byitssupporting plate 57 in order to allow for any unevenness of the sheetsurface,,and accordingly. each'coil 58' i is mounted on a hollow sleeve59 of magnetic In some instances it is desirable to provide means forpositively holding down the portions of the sheet'adjacent the cornerswhich are lifted by the lifting units 23, so that the sheet ispositively flexed to effect the initial separation thereof from the nextadjacent sheet. To this end, holding down magnets 63 may be employed,said magnets being suitably supported from the frame bymeans of rods 63.Said. holding down magnets are preferably of a type described andclaimed in a c'o-pending application and are adapted to hold down thesheet while it is initially flexed'and thereafter to lift the held downportion of the-sheet from the stack. Referring to Fig. 1, each magnet 63comprises two operating coils 64 and 65 that are separated by'a plate 66of suitable non-magnetic, material such as brass. ,A double actingplunger is provided for the coil, comprising two magnetic; coreportions. 67 and 68 connected by a rod 69' preferably ofnon-magneticmaterial,*said rod passing freely through an opening formedin the plate 66. When'the upper coil 65 is energized, core 68 is pulledinto" the coil so that core 67 is positively heldidowna ainst thesheet.When'coil 65" is deenerg zed and coil'64 energized, the core 67 ispulled upwardly into the solenoid and by magnetic attraction liftsnthetop sheet from the pile.

' Means are provided for energizing and deenergizing the variousmagnetic circuits in timed relation whereby a continuous operation isobtained; Obviously, any suitable arrangement of circuits and operationthereof may be adapted. For purposes of illustration, the magnets arearranged indfive circuits, oneincludingthe coils 33 of the opcratingmagnet 28 in series, one including all of the electro-magnets, 58 ofboth magnetic lifting units 23in series, one including the upper coilsof the magnets 63in series,'one including the lower coils64 of themagnets 63' in seriesfand the last including the sole 'noid 48; In thearrangement now tobe described, these five circuits are. controlled byfive sets of contacts that are mechanically operated in any suitablemanner. As shown in. the drawings, five pairs of 0011133015869, 7 0,

"71,72, and 73 are arranged to be closed in timed relation by'cams74,75,i76,.77 and 78, mounted on a rotating shaft 79 driven by a magnet 28to the main 86. Contacts complete a circuit from.main 85 through-=the 81on the shaft of motor '52. Theupper con tact of. each pair maywbemountedon a stas tionaryarm 82 secured to the frame "1, and

the lower contacts mounted on a similar arm 83, the cams being arrangedto bend the lower contacts upwardly intoengagement with the uppercontacts in a manner well known-in 4 showing the arrangement of thecircuit Assuming the apparatus is ready for operation, with the feedingfingers i 39 retracted bysprings 51, and with the magnetic lifting units23 lowered into engageme'nt with the operate to' close the sets ofcontacts. 69, 70, and 71 substantially simultaneously. Contacts 69complete a' "circuit, from ma inj85 through the operating coils 33inseries of the magnetic lifting units 23- to'main 86, Cor.- tacts 71completeacircuit from'mains85 through thecoils 65 in series of themagnets top sheet of the stack 5, cams 74, and 76;,

63 to the main 86; The energizationof these circuits causes theplu'ngers 67; of magnets .63 W5 to be held positively in engag'ementwith the sheet, whil'e't'he magnetic lifting units are energized to holdthe corners'of the sheet.

and magnet 28 isenergized to lift thelifting magnet. This operationresults in bending or flexing the corners of the sheet upwardly freeofthenext adj acent'sheet, so as" swam-1 airtherebetween. After thecorners have been bent upwardly, the-high point of cam 76 passes out ofengagement with contacts which open, deenergizingthe holding-down coils65, and at the same-time cam 77 operates to close contacts"7=2. Acircuitis not-completed. from main- 85 through contacts "7 2 and coils 64 inseries ,to main 86,'and-the energizationof these coils liftstheplungers'67 which liftwith them the rear'edge crane,

top sheet. Cam 77 now'operates'to closecontacts 7 3,]completingthecircuit of solenoid 48, whereby the fingers 39 are pulled forwardly tofeed the fiieets oflthepile as above described. Preferably theliftingmagnets 23 are deenergized at this time to free the sheet by thehigh point of cam' 75 passing away from contacts 7O. Assoon as the'sheethas been pushed forward sufficient"- ly, contacts 69 and 72 arepermitted to open magnets 23. fall back into engagement with by cams 74'a-nd 77 whereupon thelifti'ng the 'next'sheet, and as soon as thevfeeding strokeis completed, contacts 73 open'and springs 51 retract thefeeding vfingers 39. The operation. is then repeated to separate. andfeed the next sheet from therpileQ "fbeveled gear 80 meshing withabeveled gear In the embodiment illustrated in .Eigs S w to inclusivethe electro-magnetiemeans described abovefor operating the magneticlifting units 23 is replaced by suitable mechanical means for liftingand lowering the magnetic lifters, the operation of this embodimentbeing otherwise the same as described above. In this embodiment themagnetic lifting units 23 are carried by arms ly of each of said shafts.In the form shown,

one of the shafts 91 carries a bevel gear 95 that meshes with a bevelgear 96 secured to a transverse shaft 97 that rotates in suitablebearings formed on the frame 1." Shaft, 97 has an oscillatory motionwhich, as shown, is provided by a rock arm 98 secured thereto,

said rock arm having a pin and slot connection '99 with a rod 100 thatis reciprocated vertically by means of an eccentric 101 secured to anextension of the shaft 79. The

i. as

wiring connections for the magnetic circuits are shown in Fig. 10, and,arethe same as Y I those shown above in Fig. 4, except that theoperating magnet 28 with its coils 33 and the contacts 69 and cam 74:are omitted. The gear ratios employed are such that theraising andlowering of the magnets 23 takes place at a suitable speed, and the:contacts 70,

71, 7 2 and 78 are operated in timed relation with the oscillation ofshafts 91 whereby the operation of the apparatus is the same .as thatdescribed above.

The apparatus above described is at once simple and economical toconstruct and operate, and provides rugged and reliable separation ofsheets one by one from a stack of sheets. The magnetic lifting unitprevents penetration of the magnetic flux through'the top sheet of thestack' and at the same time obtains suflicient lifting effort bydistributing, a flux of relatively low density over a.

relatively large area of the sheet whereby the tendency for the secondsheet to be attracted with the top sheet is largely eliminated. Apositive separation of individual sheets is afforded by the combinationof mag netic lifting units of this character with means for holding downthe adjacent portions of the sheet so that the same is positively bentor flexed prior to being elevated and fed on the pile. When the feedrollers 41 and 42 are operated at fairly high speed to move the sheetsquickly off the pile, the sheets may be fed at a very'rapid rate. Whileonly two embodiments of the invention have been described and,illustrated in the draw- .tion of said feeding means.

ings, it is apparent .that the inventionis capable of a variety ofmechanical expressions and that changes may be made in the form, detailsof construction and-arrange ment of the parts,without departing fromthespiritqof the invention. Reference is therefor to be hadto theappended claims for a definitionof the limits of the inventio What isclaimed is: I

1. In apparatus of the class described ythe .combination of a liftingmagnet adapted to lift a portion ofa sheet from a pile, av pivotallymounted arm supporting said magnet', means for rotating said arm aboutits pivot to lift said magnet, and means for feeding the lifted sheetofi the pile.

2.. In apparatus of the class described, the

combination of a magnet adapted to lift the rear portion of a sheet froma pile, api'v otally mounted supporting arm for said mag- 3. Inapparatus of the." class described. 7

means for-lifting the rear portion of asheet from a pile, a pivotallymounted supporting armfor saidmeans, a magnet'for rotating saidarm aboutits pivot to raise saidulifting means, and reciprocating means movableinto engagement with theelevatedgrear por tion of the sheet to feed itforward}: i

'. 4:. In apparatus of the olass described, ,m-eans for lifting the.rear portion of a sheet from a pile, a pivotally mounted supporting armfor said means, means for rotating said arm about its pivot to raisesaid lifting means, means movable into engagement with the elevated rearportionof the sheet to feed it forwardly, and a magnet for moving saidlast-named means.

. 5. In apparatus of the class described, the combination of anelectro-magnet adapted to life therear portion of a sheet from a pile,

a pivotally mounted supporting arm for said electro-magnet, anelectro-magnet} for rotatng said arm about its plvot'to raise said firstnamed electro-magnet, reelprocating means movable into engagement withthe elevated v rear portion of the sheet, an electro-magnet for movingsaid means, and means for intermittently energizing the first twoelectromagnets and the last named electro-ma'gnet in timed relation. i

6. Inapparatus of the class described, the

combination of a movably mounted lifting magnet, magnetie means forraising" said I magnet to lift a portion of a sheet from a pile,meansmovable to engage said elevated portion to feed the sheetforwardly,and means for energizing said magnet and mag netic means intimed relation tothe opera 7., In apparatus of, the class described,the

Combination of magneticmeans for engaging a portion of a sheet, meansfor lifting said magnetic means to raise said portion,

magnetically operable means to take the sheet from said first means andfeed it forwardly, and means for operating all of said means in timedrelation.

8; In apparatus of the class described, the combination of a sheetlifting magnet, a pivotally mounted arm supporting said magnet, a.solenoid including a-movable member, means operatively connecting saidmember with said arm to rock the latter about its pivot to lift aportion of a sheet, and means for forwarding the sheet raised by saidlifting magnet. v

9. In apparatusof the class described, a pair of lifting magnets adaptedto lift portions of a sheet from a pile, pivotally mounted armssupporting said magnets, a solenoid having a pair of oppositely movablemem= hers, and means operatively connecting each of said members Withone of said supporting arms.

10. In apparatus of the class described, a lifting magnet comprising asupport and a plurality of electro-magnets mountedfthereon, the polarityof each electro-magnet differing from that of the adjacentelectromagnet, and means for intermittently energizing said electromagnets.

I 11. In apparatus of the class described, a lifting magnet comprising asupport, and a plurality of spaced electro-magnets carried by saidsupport, said electro-magnets having a pole adjacent the pole of anotherelectromagnet and differing in polarity therefrom to provide asubstantially uniformly d1s tributed flux over the area covered by said4.0 poles, and means for intermittently energizing. the electro-magnets.

12. In apparatus of the class described, a support and a plurality ofsheet separating electro-magnets carried by said support and eachmovable relatively thereto, each electrolifting electro-magnetcomprising support rality of spaced cores car said means,

ing means of magnetic material and a plu l a pole of each core havingpolarity difier- I ing from that of an adjacent pole of an adjacent coreto provide a substantially uniformly distributed flux over the areacovered energizing said electro-magnets.

EDWIN s. LINCOLN.

specification. W

magnet having a pole adjacent the pole of I an adjacent e'lectro-magnetand differing in polarity therefrom, and means for intermittentlyenergizing said electro-magnets.

13. In apparatus of the class described, a

, lifting magnet comprising a support, a plurality of members ofmagnetic materialcarried thereby and movable relatively thereto,

and an energizing coil carried by each of said members.

14. In apparatus of the class described, a lifting magnet comprising asupport, a plurality of members of magnetic materialcarried therebyandmovable relatively thereto,

and an energizing coil carried by eachof said members, said coils beingconnected for energization from a common source and being Wound toprovide adjacent poles of unlike polaritv.

15. In apparatus of the class described, a

by said poles, and means for intermittently C

